He continued about how the E! News host is embracing her new role as a mother.

“It’s amazing how maternal instincts have taken over, and Giuliana’s just supermom. It literally brought tears to my eyes the other day watching her with Duke,” Bill said.

Baby Duke’s arrival has come after years of hardship. The couple have spoken openly about their miscarriages, infertility and Giuliana’s breast cancer diagnosis in December 2011.

“I couldn’t believe that all those years of struggling and the tears actually paid off,” Giuliana told the magazine, on newsstands now, “Every shot, every doctor’s visit—in the end, when you’re holding your baby in your arms, you forget it all, and it’s worth it.”